carbon fiber unstayed masts in cold and high UV environments

[gmat]

I have been looking at the carbon fiber unstayed masts on various yachts (the Sponberg designs, Wylecats, the Tanton designs, etc).

I like the whole idea. But I have a question about environmental factors.

How does the performance of the carbon fiber unstayed mast change in very cold weather (e.g. arctic sailing), or a high UV environment like the tropics? My guess is that the environmental factors have no short term impact, but the UV may have some long term effect if you spend a lot of time in the tropics ...

 

[michael pierzga]

No idea about cold unstayed masts.

I have a carbon mast and it seems impervious to cold.

The mast is 21 years old.

Uv is a danger, but since a mast is painted its not an issue.

 

[Stumble]

Gmat,

Carbon is pretty much impervious to cold weather. There may be some micro-fracturing, but we a re talking about completely meaningless in the scheme of things. CF is commonly used in aerospace satellites in part because of its minimal coefficient of thermal expansion. If it can handle the cold of space I doubt that anything the arctic can throw at it will matter.

UV is a real concern, but protective clear coating is a pretty well understood process. As is painting.

 

[michael pierzga]

Cold...freezing is very aggressive to mechanical fasteners and mechanical joints.

Best avoid these in your design

 

[gmat]

About satellites and the use of carbon fiber. The thing I wondered about is flexibility. In the cold the mast must maintain it's flexibility to function correctly. For a satellite are they building flexible parts out of carbon fiber?

 

[Eric Sponberg]

How does the performance of the carbon fiber unstayed mast change in very cold weather (e.g. arctic sailing), or a high UV environment like the tropics? My guess is that the environmental factors have no short term impact, but the UV may have some long term effect if you spend a lot of time in the tropics ...

The performance of carbon fiber laminates in harsh environmental conditions has more to do with the performance of the resin than it does the fiber. In very cold climates, carbon fiber composites do very well, witness its use in commercial jetliners and military aircraft that fly very high in very cold atmospheres. No problems there.

It is also always best to paint the laminate to protect the resin from UV light degradation. This is why carbon fiber masts and airplanes are painted.

Eric